Yes, the goal is to have a bit of "black border" all around every character, im going to show 2 images as example but as i said this is hard to achieve and im not sure if is posible to do it accuratelly, in a image editor app (photoshop, gimp, etc) is easy but with graphic libraries for PS3 im not so sure how much tricky could be to achieve this effect
Also, in this example im pushing this to the extreme of the worst posible scenario, with a "white font on top of white background", lol
The point is is you achive to do this with "white on white" it becomes failproof for all other colors, it gives you 100% freedom to choose whatever you want with the font and background colors
In the actual PKGi the shadow have the same size than the font, and seems to be displaced X+4 and Y+4
And this is (in my oppinion) what you should try to achieve
The trick is... if you want to move the shadow a few pixels... then the size needs to be increased a few pixels + a bit more
Some examples...
For shadow offset +4.... size should be +6 or so
For shadow offset +10.... size should be +13 or so
For shadow offset +20... size should be +25 or so
In the first example i mentioned, using shadow offset +4 and size +6 is pretty close to what you was doing... this would create shadows of 4 pixels in a direction... and a thin border of 2 pixels in opposite direction (because 6-4=2)
It doesnt needs to be very notable... also this is not a visual effect intended to look great, is mostly a prevention to avoid problems, and most of the time (in dark areas of the background) this effect is not going to be notable
In the image i made with photoshop was easyer because it was at big resolution and the shadow is a degrade.. but in the PS3 graphic libraries with the trick you are using rendering the texts 2 times doesnt works like that, the shadow at bottom will have "sharp edges"
So try to see if you can get close to that, but dont get crazy with it, is just an small detail
